Fluid treatment, often called stimulation which includes fracturing, of a formation typically increases the production from that formation by a large factor. The increase in some formations only lasts about 10-18 months. In these wells it is beneficial to restimulate the formation to increase the existing fractures or to make more fractures, both of which contact more hydrocarbons. After a restimulation, the well production is typically increased, sometimes to a level close to that after the original stimulation because of the increased contact with new hydrocarbons. There is a need to provide a tool that will make re-stimulation on a previously treated stage easy and affordable. While some have suggested re-stimulation by running in with a string to close and to reopen ports, this is time consuming.